buckingham



(No Model.) 2 Sheets-Sheet 1. 0. L. BUGKINGHAM.

REGULATOR FOR ELECTRIC LAMPS. No. 310,119. v I Patented Dec. 30, 1884.

(No Model.)

0. L. 'BUGKINGHAM.

REGULATOR FOR ELECTRIC LAMPS.

2 Sheets-Sheet 2 Patented Dec. 30, 1884.

1 r a, L 71 L1 m I ii e EH1 'PHII.

wi t Memes UNITED STATES Parrrrr @rrrca.

CHARLES L. BUGKINGHAM, OF NEXV YORK, N. Y.

REGULATOR FOR ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 310,119, dated December30, 1884.

Application filed May 5. 1884. (No model.)

1" 0 all whom it may concern.-

Be it known that I, CHARLES L. BUOKING- HAM, of the city, county, andState of New York, a citizen of the United States of America, haveinvented a new and useful Improvement in Regulators for Electric Lamps,of which the following is a specification.

The various types of existing differential lamps are provided with twocoils. Qne of said coils, commonly known as the coarse wire coil, formsa part of the are branch, and serves to separate the carbon electrodesof the lamp to establish an arc, while the other coil, commonly known asthe finewire coil, and being included in a shunt to the electric lamp,acts to overcome the force of the coarsewire coil and to cause theelectrodes of the lamp to be fed together under the positive ac tion ofa spring, gravity, or other agent. I employ, instead of' a singlecoarse-wire coil, two coarsewire coils, forming parts of two brancheswhich begin and reunite on the same side of the arc. Said coarse-wirecoils are wound either differentially upon a single electromagnetic coreor upon independent cores in such a manner as to afford an opposing ordifferential action in respect to each other. One of the branches is ofconstant electrical resistance, while the resistance of the other isreadily adjustable, and adjustment in its resistance is effected by anelectro-magnet whose coils form a part of a high-resistance shunt aroundthe lamp. Normally, very little current flows through the shunt branch,and at the same time very little, if any, current passes through thatone of the coarse-wire coils embracing the variable resistance, as saidresistance is then at its maximum and many times greater than that ofthe other branch. Nearly the entire current of the main circuit, underthis condition, is forced through the coarse-wire coil whose branch isof a constant resistance, and thereby the electrodes are held apart toform an arc. hen, however, the electrodes are consumed to an extent tooccasion an increased are resistance, more current is diverted throughthe fine-wire shunt and to an extent proportional to the increase of areresistance. Theinerease of current in the shunt branch causes thearmature of the electro'magnet therein. to automatically decrease theresistance of the branch of one of the coarse-wire coils, therebypermitting more current to pass through it, which acts to neutralize theeffect of the current in the other coarse-wire coil. If the twocoarse-wire coils are wound upon the same core, the resultantelectromagnetism may thus be reduced, and, if need be, rendered nil. Ifthe two coarsewire coils are wound one upon stationary cores and theother upon movable electromagnetic cores normally, the poles of themovable core by inductive effects will be held against the action of aspring or gravity opposite to or in the immediate proximity of the polesof the stationary core, and upon a decrease of the variable resistancein one of said branches magnetism will be induced which will neutralizethe effects whereby the stationary and movable cores are held close toeach other, thereby permitting the retracting force acting upon themovable cores to cause the carbons of the lamp to be fed together. It isobvious that in the old types of differential lamps a very considerableincrease of arc resistance must occur before enough current will bediverted through the fine-wire coil to effect a feed of the electrodes.lVith my arrangement, however, it is apparent that an increase ofcurrent, although too small to in any considerable degree neutralize theeffect of the strong are branch current, will yet be suiiicient toactuate an armature of the shunt electro-magnet for the purpose ofremoving a part or the whole of the variable resistance of one of thebranches.

1 will now describe my invention by reference to the accompanyingdrawings.

Figure 1 shows a regulator whose feed-magnet is provided with an axialarmature, and upon whose core are differentially woundtwo coarse-wirecoils. Fig. 2 represents a magnet system for the feed-regulator,consisting of a stationary and a movable electro-ma-gnet whose coilsrespectively form parts of the two multiplearc branches of the mainline.Fig. 3 is a side view of the oscillating feed-magnets and feed-clutchapparatus.

As shown in Fig. 1, L is a main line which is divided at points a andI), both on the same side of the are, into two branches, Z and Z, whosenormal resistances may be about as one to ten, including, respectively,coils in and n of clcetro-magnet Til. Coils m a are wounddiil'erentially upon the core ol'electro-magnet M, whereby th e currenti'lowin g through branch Z tends to neutralize the magnetic effects inthe electro-magnet M due to the current in branch 1. Branch 1 is ofconstant electrical. resistance. lranch Z completes its circuit throughlever G and an adjustableresistance, 1, thus atl'ording in said branch ahighly-variable conductivity. Resistance 11 is made up ola pile ofcarbon plates laid llatwisc upon one another, and the resistance of thepile is varied by a variable pressure, to which it is subjected by meansol' eleetro-magnet E.

a is a shunt of high resistance joining the opposite poles of theeleetriclamp and including the fine-wire coils of clectroanagnet E.Electro-magnet 11 is provided with an axial armature attached to thearmature-lever C, which is pivoted at point.- a'. When no current isflowing through shunt s, the resistance of branch Z is at its maximum,since at that time the armature ol' the shunt-magnet is un attracted andthe armature-lever G bears only with a light pressure upon the plates ofthe carbon resistance R. ll" the current strength in shunt 8, however,is increased, armature lever G compresses the carbon resistance it untilits conductivity is greatly increased. The wire of coil 11. should besomewhat smaller than that of coil or, and their respective amounts orwire should be so proportioned that their resultant magnetic effectswhen the resistance of it is reduced to its minimum will be almost ail.

Although the maximum resistance of It may be great as compared with theresistance of branch Z, it need not exceed one ohm, for even with thatsmall amount not enough current would flow through its branch. to causethe heating of the carbon pile, owing to the still smaller resistance01' the branch I. if the re sistance of R is, say, one ohm when nopressure is applied, it is obvious that only a small force would berequired to reduce the resist ance to an extent tocause much morecurrent to How through its branch.

II is a carbon-holder carrying carbon electrode 13, and r is the axialarmature of differential magnet I, through an axial opening of which thecarbondioldcr passes. A stirrup, c, carrying a supporling-ring, throughwhich the carbon-holder also passes, is pivoted to the axial armature atr, and a lever, 71, ispivoted to supporting-ring tat 1:. Lever/iisprovided with a claiupingtoc, U, to r engaging with or releasing thecarbon-holder ii, and is also provided with a spring, 0, attached to arigid support, 3 which carries a set-screw, I for arresting the downwardmovement of lever 7i. "W hen the axial arn'iaturc G is lifted byelcctro-magnet M, the supportingring t is raised, carrying with it thepivoted support 0 of lever 71, and the opposite end of It is retained ina nearly-constant position by spri ng 0 until toe to is iirmly clampedagainst the carbon-holder, whereupon said lever is then lii'ted againstthe tension of spring 0 from its seat on set-screw Under this conditioncarbon F is lifted from carbon (r to form an are between their points.If while lever h is lifted :l'rom set-screw q the axial armature r islowered, said lever it will first strike set-screw q, and upon a furtherl i wering of the axial armature lever 71. will be tilted until the tooa releases carbon-holder 1!, thereby permitting the carbon points tofeed together. Themain circuit .li divides at point (6 into threebranches, the sluint-branch .s and branches H, which are reunited atpoint Z) into the single-arebranch conductor connectii'ig with brush 1and the carbou-holder H. The are and shunt branches reunite at point dat the opposite side of the are.

The operation of the lamp is as follows: Vhcn no current is flowing uponthe main line, the-carbon points F and G rest in c011- t-act, and theresistance of branch Z in respect to that of Z is comparatively great.It" a current of normal strength is now passed over the main line,nearly the entire current will l'low through branch Z, causing thecarbon points to be separated to form an are. It, however, theresistance of the arc becomes too great, considerz'ible current willi'low through shunt s, which immediately removes resist ance l'roinbranch Z until the magnetism due to coil n nearly neutralizes that of m,thus permitting axial armature g to drop until lever It strikesset-screw q and toe w releases carbon-holder H. hen by this means aproper feed has occurred, the arc-branch resistance will have been sofar reduced that verylittle current will 'llow through the shunt branch,and the resistance of branch Z will be so far increased that coil 11.will nolongerproduce any considerable neutralizing eitect.

Fig. 2 shows an apparatus which is modified in respect to that of Fig. 1only in the form of the i'cedanagnet arrangement.

'11 is the coil of a stationary clcctro-magnet whose horizontal coresare in the same vertical plane.

in is the coil oi an oscillating electro-magnet whose cores are pivotedupon a horizontal axis. \vheu little current ilows through coil in, thecores of a induce opposite magnetism in the cores of m, and the cores ofm and 01 are attracted and held opposite each other. The current inbranch I induces in the cores ol' m magnetism oi the same polarity asthat in the cores of a, thereby neutralizing in the cores otm magnetismwhich is induced in them by the cores 01 02, thus permitting the coresof 'H! to oscillate and lower supporting-ring l, which is connected tosaid eleet-ro-magnet by the jointed arm 0 and pin 5/, until thecarbonholder is nuclamped by too in and a carbont'ecd e'ii'ectcd.

instead of a resistance, .1, composed of a series of compressible carbonplates, I may use any well-known form of rheostat; but by means of theform of adjustable resistance here shown the conductivity of Z may begradually increased and decreased. Instead of an adjustable resistance,I of course may employ armature-lever O to open and close branch Zwithout any intermediate change of resistance in said branch; but undersuch conditions of operation the magnetic effects in the lifting-magnetwould always be either neutral or at their maximum.

My invention is equally applicable to all forms of differential lamp-regulators. I therefore do not desire to limit myself to thearrangements of magnets for controlling the carhon-feed herein shown.

The relative resistance of branches Z and Z and the size and length ofwire employed in each branch may be greatly varied. It is necessary,however, that they should be so proportioned that the magnetic effectsof the two coils may be rendered substantially equal when the resistanceof R is reduced to a minimum.

WVhat I claim, and desire to secure by Lettcrs Patent, is

1. In an electric lamp, two main line branches including opposingelectro magnetic coils, an adjustable resistance in one of saidbranches, and a shunt embracing an electromagnet joining the oppositepoles of the lamp, for controlling said adjustable resistancc.

2. In an electric lamp, two branches which begin and reunite at one sideof the electric are, elcctro-magnet coils in each of said branches, anadjustable resistance in one ol. said branches, and an electro-magnet ina shunt around the lamp, for controlling said adjustable resistance.

3. In an electric lamp, two main line branches beginning and terminatingon the same side of the are, one of which is of constant resistance andembraces the electromagnetic coils for establishing an arc, and theother of variable resistance, which embraces the electromagnetic coils,for causing the carbons to feed.

In an electric lamp, the combination of branches ll, adjustableresistance It, differential coils m 12, shunt s, and electro-magnet E.

.3. In an electric lamp, the combination of branches ZZ, differentialcoils m a, shunt s, and electro-magnet E.

6. In an electric lamp, a coarse-wire branch, Z, including feed-coil aand an adjustable re sistance, R, as set forth.

7. In an electric lamp, the combination of branch Z, including coil 02,and resistance It, and shunt 8, including means for controlling 60 saidresistance.

Executed April 22, 1884-.

CHARLES Ii. BUCKINGHAM. lVitnesses:

\Vir. ARNOUX, S. S. Wa'r'rims.

